The present invention relates to power tools for and methods of moving elements relative to an object, for example for moving a nut which is screwed on a bolt, a head of a bolt, etc.
Power tools of the above mentioned general type are known in the art. Known power driven torque tools have an action and an opposite reaction force. The action force is usually exerted by a drive member adapted to turn an element. The reaction force is usually transferred to an object adjacent to the element to be turned, by means of a reaction bar. The reaction bar is usually connected to the tool housing. This way only one of the two opposite forces is being used.
A power tool for this purpose is disclosed in my U.S. Pat. No. 5,499,558. The tool has a coaxial action and reaction, and corresponding action and reaction applying parts. However, only one of them turns while the other stands still. It does not provide application of opposite turning forces of a power tool action and reaction simultaneously to one or several members, so as to turn them in the same direction.
My U.S. patent application Ser. No. 08/957,618 discloses a nut member having a plurality of geared screw members screwed into it. FIG. 3 shows an embodiment for turning the screws simultaneously by applying a turning force to the outer circumference of the gears, while FIG. 4 shows an embodiment for turning the screws simultaneously by applying a turning force to the inner circumference of the gears.
In the known power tools of this type there are three negative forces than can act when a bolt etc is stretched via a torque: a side load, a bending force and a torsion. If a torque wrench is used and only one drive is applied to turn the screws, three things can occur:
the tool would have to react against a nearby stationary object, causing a side load to the ring member; PA1 if the turning friction of the screws exceeds the friction of the abutment of one end of the screw members, the ring-type member could turn causing torsion; PA1 if the gear head of one screw bends slightly and skips the tooth engagement, then the screw would not extend equally with the others causing a bending force of the ring-type member.